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[ginac.git] / ginac / parser / parser.cpp

diff --git a/ginac/parser/parser.cpp b/ginac/parser/parser.cpp
index 78a03f81df0401f9f220f4955c276f0c036e5240..df616a41fcfe18307135234bf2cab0d1b95a3cb6 100644 (file)
--- a/ginac/parser/parser.cpp
+++ b/ginac/parser/parser.cpp
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's parser. */
 
 /*
- *  GiNaC Copyright (C) 1999-2010 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2020 Johannes Gutenberg University Mainz, Germany
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -21,17 +21,49 @@
  */
 
 #include "parser.h"
+#include "lst.h"
 #include "lexer.h"
 #include "debug.h"
 #include "mul.h"
 #include "constant.h"
 #include "function.h"
 
+#include <cstdint> // for uintptr_t
 #include <sstream>
 #include <stdexcept>
 
 namespace GiNaC {
 
+// <KLUDGE>
+// Find out if ptr is a pointer to a function or a specially crafted integer.
+// It's possible to distinguish between these because functions are aligned.
+// Returns true if ptr is a pointer and false otherwise.
+static bool decode_serial(unsigned& serial, const reader_func ptr)
+{
+       uintptr_t u = (uintptr_t)(void *)ptr;
+       if (u & 1) {
+               u >>= 1;
+               serial = (unsigned)u;
+               return false;
+       }
+       return true;
+}
+
+// Figures out if ptr is a pointer to function or a serial of GiNaC function.
+// In the former case calls that function, in the latter case constructs
+// GiNaC function with corresponding serial and arguments.
+static ex dispatch_reader_fcn(const reader_func ptr, const exvector& args)
+{
+       unsigned serial = 0; // dear gcc, could you please shut up?
+       bool is_ptr = decode_serial(serial, ptr);
+       if (is_ptr)
+               return ptr(args);
+       else
+               return function(serial, args);
+}
+// </KLUDGE>
+
+
 /// identifier_expr:  identifier |  identifier '(' expression* ')'
 ex parser::parse_identifier_expr()
 {
@@ -61,24 +93,15 @@ ex parser::parse_identifier_expr()
        // Eat the ')'.
        get_next_tok();
        prototype the_prototype = make_pair(name, args.size());
-       prototype_table::const_iterator reader = funcs.find(the_prototype);
+       auto reader = funcs.find(the_prototype);
        if (reader == funcs.end()) {
                Parse_error_("no function \"" << name << "\" with " <<
                             args.size() << " arguments");
        }
-       // dirty hack to distinguish between serial numbers of functions and real
-       // pointers.
-       GiNaC::function* f = NULL;
-       try {
-               unsigned serial = (unsigned)(unsigned long)(void *)(reader->second);
-               f = new GiNaC::function(serial, args);
-       }
-       catch ( std::runtime_error ) {
-               if ( f ) delete f;
-               ex ret = reader->second(args);
-               return ret;
-       }
-       return f->setflag(status_flags::dynallocated);
+       // reader->second might be a pointer to a C++ function or a specially
+       // crafted serial of a GiNaC::function.
+       ex ret = dispatch_reader_fcn(reader->second, args);
+       return ret;
 }
 
 /// paren_expr:  '(' expression ')'
@@ -93,8 +116,35 @@ ex parser::parse_paren_expr()
        return e;
 }
 
-extern numeric* _num_1_p;
-extern ex _ex0;
+/// lst_expr:  '{' expression { ',' expression } '}'
+ex parser::parse_lst_expr()
+{
+       get_next_tok();  // eat {.
+
+       lst list;
+       if (token != '}') {
+               while (true) {
+                       ex e = parse_expression(); // expression();
+                       list.append(e);
+
+                       if (token == '}') {
+                               break;
+                       }
+
+                       if (token != ',') {
+                               Parse_error("expected '}'");
+                       }
+
+                       get_next_tok();  // eat ','.
+               }
+       }
+       // Eat the '}'.
+       get_next_tok();
+
+       return list;
+}
+
+extern const ex _ex0;
 
 /// unary_expr: [+-] expression
 ex parser::parse_unary_expr()
@@ -108,7 +158,7 @@ ex parser::parse_unary_expr()
        // -(a) 
        // +a
        // +(a)
-       // Delegete the work to parse_binop_rhs(), otherwise we end up
+       // Delegate the work to parse_binop_rhs(), otherwise we end up
        // duplicating it here. 
        ex lhs = _ex0; // silly trick
        ex e = parse_binop_rhs(0, lhs);
@@ -125,6 +175,8 @@ ex parser::parse_primary()
                         return parse_number_expr();
                case '(': 
                         return parse_paren_expr();
+               case '{': 
+                        return parse_lst_expr();
                case '-':
                case '+':
                         return parse_unary_expr();